Growpito Demo Grow

What is your starting water EC or is 1.3 EC just the nutrient additions? How often is the reservoir changed?

Mañ'O'Green said:

What is your starting water EC or is 1.3 EC just the nutrient additions? How often is the reservoir changed?

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My starting EC is 1.3 - my tap is .2 with another .2 of calmag and .9 from prescription blends nutrients.

I do not change the reservoir, I keep it under 75f in the summer to prevent anaerobic bacteria, and I top it off based on water amount and EC at the time. I may go three weeks, 7 fertigations, but still be at 1.2-1.3. if the EC changes too much, especially with reduced water levels I refill it 1/2 strength. No reservoirs changes or waste water.

I'm running a 55 gallon whereas with our instructions I'd be running a 25 gallon reservoir. It's easier to maintain the larger reservoir imo

IMPO your nutrients will get out of balance running hydro like that. What happens is the plants will use the nutrients that they want and leave the others behind. You are replacing them in balance but the nutrients that remain just get stronger and stronger until you have a lock out situation. This is the reason DWC needs to be changed weekly. Now it is true that with the large volume you will have a better buffering capacity but that will only work for so long?

How much does it cost to mix up the 55 gallons? Will you be changing the formula as the plants mature?

Mañ'O'Green said:

IMPO your nutrients will get out of balance running hydro like that. What happens is the plants will use the nutrients that they want and leave the others behind. You are replacing them in balance but the nutrients that remain just get stronger and stronger until you have a lock out situation. This is the reason DWC needs to be changed weekly. Now it is true that with the large volume you will have a better buffering capacity but that will only work for so long?

How much does it cost to mix up the 55 gallons? Will you be changing the formula as the plants mature?

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Swings in pH or EC are usually indicators for me that the reservoir needs adjustment. Not really the intention to let the reservoir hit half capacity but I do continually adjust the pH and EC just less often with a larger capacity.

I have not ran this particular nutrient in the 55 gal before but I have ran Mega Crop, I still have a lot. I've had to run it lighter because of the issues you spoke of and taper it mid to late flower. I've used Botanicare Pure Blend Pro with Liquid Karma and that has worked quite well for me and coalminer.

I will be following PBN's instructions with this especially as I have never flowered these out.

I am not sure you are following my thinking. Lets say you start with N-P-K at 10-10-10 EC 1.3 after the first week the plants have used 4-2-1 leaving 6-8-9 EC1.0 so you add 10-10-10 to get the EC back to 1.3 You have no way of knowing what nutrients the plants have used so you just add them back in balance but now your ratios are 6-8-9 and again the plants consume 4-2-1. now you are left with 2-6-8 when you add 10-10-10 again you remain at 2-6-8 and your nutrients are out of balance. If you do not start with a fresh reservoir you have no idea what is in there. Sure the EC is 1.3 but what is the make-up of that 1.3?

Mañ'O'Green said:

I am not sure you are following my thinking. Lets say you start with N-P-K at 10-10-10 EC 1.3 after the first week the plants have used 4-2-1 leaving 6-8-9 EC1.0 so you add 10-10-10 to get the EC back to 1.3 You have no way of knowing what nutrients the plants have used so you just add them back in balance but now your ratios are 6-8-9 and again the plants consume 4-2-1. now you are left with 2-6-8 when you add 10-10-10 again you remain at 2-6-8 and your nutrients are out of balance. If you do not start with a fresh reservoir you have no idea what is in there. Sure the EC is 1.3 but what is the make-up of that 1.3?

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You're speaking of nutrient antagonism correct? I'm following however I've yet to experience these issues. I believe by providing low nutrient strength these become non issue especially in a larger reservoir equilibrium is more easily maintained. However nutrient uptake depends on many factors beyond the reservoir - environmental variables are at play as well that will have an impact.

I think it's a valid question that many have researched but commercial SOPs for produce reflect changing the reservoir every so often just in case. Some studies have shown injection of NPK to maintain balance but usually there is no improvement or detriment to plant biomass.

This looks like it’s going be a good show! @Growpito_Aleks thanks for including our nutrients in your grow, I like how your explaining how your system is setup and how it run. Definitely following along for this!

Prescription Blend said:

This looks like it’s going be a good show! @Growpito_Aleks thanks for including our nutrients in your grow, I like how your explaining how your system is setup and how it run. Definitely following along for this!

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Much appreciated. The nutrients are simple and effective to use just like our Sim mix. I'm not seeing CaMg issues thankfully as I believe the 40%> humidity and allowing the pH to swing between 5.5 and 6.5 is allowing proper transport.

Nice grow, they're looking great there.
I was having the same concern as @Mañ'O'Green about topping up rather than starting fresh.
Sure, if you let the old res get really low before you top up, less of a problem, but still...
They look good for now, though.
All the best for the second half of the flowering game!

Shiva's Mistress said:

Nice grow, they're looking great there.
I was having the same concern as @Mañ'O'Green about topping up rather than starting fresh.
Sure, if you let the old res get really low before you top up, less of a problem, but still...
They look good for now, though.
All the best for the second half of the flowering game!

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With this current grow I've been topping up roughly every other week. I have not dumped the res once this entire grow and I've maintained the EC fairly low throughout. The pH has been allowed to drift between 5.5 - 6.2 with the only real difference behind the higher dosing of Big Data.

We've figured it's easier to show rather than tell lol. Appreciate the kind words and I hope you enjoy the grow.

Girls r looking great.

I never change my 15 gallon, multiple plant reservoirs in DWC unless there's a problem. I do empty out and replace 1/2 gallon daily for testing, and add clorox daily.

Those worries about elements getting out of whack with each other just don't happen, because the plants stay healthy.
I have noticed no difference between doing the usual res changes, and never changing.
A lot of fertilizer and water runs thru the system, and plants have some ability to pick and choose what to eat.
Solid media growers and autopot users don't change out their grow-media either mid-grow.

Life is so much simpler in hydro not changing the reservoir.